There are many moderate sized hydroelectric power plant operations throughout the United States and elsewhere running antiquated and worn out quad turbines to drive power generators in places where the power demand for generation capacity of an older quad unit power plant remains, but the operational cost per unit of power delivered out of the plant, even when the original quad turbine unit is maintained in as currently a cost effective and optimally mechanical state of operation as possible, is simply not competitive with power generated by other means within the grid. Under the foregoing circumstances, the option is to up-grade the original equipage quad turbine unit with a modern turbine unit of greater operational efficiency and lower maintenance and manning costs. The draw-back problem of exercising a turbine up-grade replacement option under circumstances of the foregoing conditions, however, is that the design profiles of currently available up-grade turbine replacement units are not mechanically compatable with the existing power plant quad unit civil structure, and as a cost of up-grade turbine unit replacement one has not only the new turbine plus turbine control and auxiliary costs, but is also confronted with a frequently more substantial and additional civil structure re-work and construction cost to accommodate the installation and support of the up-grade turbine unit. The result is that the turbine up-grade replacement option usually becomes no longer economically feasible, that is, the total capital cost burden is not recovered by operational revenues in a reasonable time.
The present invention relates to a practical and economic up-grade turbine replacement unit based on a duplex design, which optimizes replacement economies by minimizing civil engineering modification costs in effecting its installation and replacement of a quad unit. The duplex turbine unit of present invention also incorporates the unique mechanical feature of protectively housing the wicket gate control mechanism and adjustment linkages within the turbine casing to thereby protect the same from being damaged by entrained debris in the turbine water.
The major construction changes that are typically encountered in adapting an existing power plant civil structure from a quad turbine installation to an up-graded operation employing say a bulb, pit, or S-turbine are generally as illustrated and described in FIG. 4 on Page 22, of the Sept., 1988, issue of "Water Power & Dam Construction", and as therein shown the civil structure re-work and modifications involve a major construction project. And, as previously pointed out, frequently the determinative factor is not the capital cost of the up-grading turbine replacement unit but rather the capital construction cost in preparing the power plant site to receive that unit.
A typical duplex profiled turbine unit as shown in German Pat. No. 327,160 dated Feb. 26, 1920, which has a single runner with blades on both sides of the hub and a corresponding double discharge, utilizes pressurized water rather than an open flume source, and has a single set of wicket gates with the adjustment mechanism therefor exterior of the turbine casing. A teaching showing the wicket gate adjustment mechanism interior of a power station housing, but not the turbine casing, is as set forth in U.S. Pat. No. 4,224,526 to Margison et al dated Sept. 23, 1980.
The duplex turbine and associated running gear for the generation of electrical power is not per se new. What is new in terms of the turbine structure is the novel manner in which the various elements and components are assembled in order to provide unique and useful results not heretofore known, and secondly in terms of utility the manner in which the new and novel turbine profile is used as an up-grade replacement turbine unit in combination with an existing power plant civil structure without the need or necessity for major and expensive re-working thereof so that now an alternative turbine replacement unit up-grade option is available which provides the operational economies of an up-graded turbine unit without the prohibitive civil structure modification and re-work capital construction cost.